Balance the following chemical equations. 1. Al + HCl → AlCl3 + H2
2. Al+S → ALS:
3. NO2 + O2 + N2O5
4. A1,03 → A1+ O2
5. Ba(C103)2 → BaCl2 + O2

The basic principle of the number of elements in reactants and products is the same used in balancing chemical equations

Given

The chemical equation

Required

The balanced equation

Solution

Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:  

•1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.  

•2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product  

•3. Select the coefficient of the substance with the most complex chemical formula equal to 1

We give an example for reaction number 1:

aAl + bHCl → AlCl₃ + cH₂

Al, left = a, right = 1⇒a=1

Cl, left = b, right = 3⇒b=3

H, left = b, right = 2c⇒b=2c⇒3=2c⇒c=3/2

The equation becomes :

Al + 3HCl → AlCl₃ + 3/2H₂ x2

2Al + 6HCl → 2AlCl₃ + 3H₂

The steps are the same for the other reactions

2. 2Al + 3S → Al₂S₃

3. 4NO₂ + O₂ → 2N₂O₅

4. 4Al + 3O₂ → 2Al₂O₃

5. Ba(ClO₃)₂ → BaCl₂ + 3O₂

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.